Composite metal article and method of joining the parts thereof



1937- c. M. UNDERWOOD El AL 2,071,050

COMPOSITE METAL ARTICLE AND METHOD OF JOINING THE PARTS THEREOF Filed June 9, 1934 FIG.

'Patented Feb. 16, 1937 UNITED. STATES PATENT OFFICE I COMPOSITE METAL ARTICLE AND METHOD OF JOINING THE PARTS THEREOF Carl M. Underwood, Newton Center, Mass., and Arden L. Van Nest, Oak Park, Ill., assignors to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York Application June 9, 1934, Serial No. 729,742

r 1 Claim.

This invention relates to composite metal articles and methods of joining the parts thereof, and more particularly to 4 composite articles wherein the parts are joined end to end, and methods of joining the same.

Objects of this invention are to provide an improved composite metal article and an improved and efllcient method of producing an end to end joint between the parts thereof.

In accordance with the above objects, wherein one embodiment of the invention is applied to the production of composite screw driver blades comprising a blade portion and a shank portion integrally joined in end to end relation, the blade portion is made smaller in cross-sectional area than the shank portion, and a sleeve is fitted tightly upon the inner end of the blade portion, its inner end having a diameter substantially the same as the diameter of the shank portion. The end area of the shank portion is then electrically welded to the end area of the blade portion and to the annular end area of the sleeve to form an integral sturdy unit. a

Other objects and advantages of this invention will more fully appear from the following description taken in connection with the accompanying drawing, wherein Fig. 1 is a fragmentary side view, partly in section, of a screw driver comprising a composite blade embodying the features of and produced in accordance with the method of this invention;

Fig. 2 is a transverse section, on an enlarged scale, taken on the line 2--2 of Fig. 1;

' Fig. 3 is a detached fragmentary enlarged side view of the inner end of the screw driver blade portion;

Fig. 4 is a detached enlarged side view of the sleeve which is fitted upon the inner end of the blade portion;

Fig. 5 isa detached enlarged side view of the shank portion of the blade, and

Fig. 6 is a fragmentary enlarged vertical longitudinal section of the blade portion, sleeve and shank portion after being welded into an integral unit and with thewelding flash removed.

A composite screw driver blade embodying the features of this invention may be produced according to the following method. Referring to tional area than the blade and in the completed screw driver, as shown in Fig. 1 is anchored in a handle I2, the shank portion H being of a suitable length cut from soft steel rod stock having a relatively low carbon content as compared to the blade to reduce manufacturing costs. The rod stock from which the shank portion 1 I is cut, in the present embodiment, is formed with four equally spaced longitudinal ribs or fins l3 serving in the completed screw driver to anchor the handle to the shank portion to prevent turning therebetween.

Surrounding the inner end of the blade portion Ill and having a tight fit thereon is a shouldered sleeve or collar [4 which like the shank portion ll is made from soft steel of relatively low carbon content to reduce costs. At its inner and smaller end the sleeve M has an outside diameter substantially the same as the shank portion. After assembling the sleeve M on the blade portion H), the two members being substantially flush at their inner ends, they are brought into abutting parallel end to end relation under suitable pressure with the shank portion II and in axial alinement by means of a suitable fixture, not shown. Thereafter the inner ends of the blade portion to and the surrounding sleeve ll are integrally united to the abutting end of the shank portion II by electric welding efiected by the usual methods employed in butt welding. The usual flash of metal at the point of weld is then removed by grinding, or otherwise, and the united v parts along their welded areas then appear as shown fragmentarily and in section in Fig. 6, the line of welding being indicated at l5. v

Due to the equal alined end areas of the shank portion II and the .blade portion l0 taken with the annular end area of the surrounding sleeve l4, one portion of .the composite bladedoes not sink into the other While the metals are in a plastic or semifluid condition, due to the welding current, but remain flush. The inner end of the sleeve I4 welded to the shank portion ll provides an annularly-shaped abutment to absorb lateral thrusts of the blade portion ID of the composite screw driver blade when in use. Also, since the blade and shank portions Ill and II, respectively, must be assembled in axial alinement the referred to equal end areas serve to facilitate the checking thereof for this alinement.

The outer or operative end of the blade portion is then finished by suitable forging and machining operations to the shape shown in Fig.

. made of suitable wood or other material.

1. Thereafter the finished composite blade is assembled with the handle l2, which may be The handle I! carries at one end a tapered metal ferrule l6 driven onto a similarly shaped peripheral surface of the handle and engaging at its inner end an annular surface of the handle. Formed axially in the handle l2 along the tapered end is an aperture ll of a suitable diameter and length for receiving the inner end of the composite blade. The diameter of the aperture I1 is less than the overall diameter of the shank portion ll, including the fins l3 (Fig. 2), so that when the handle is driven onto the composite blade the fins will cut into the material of the handle and effectively anchor the handle to the blade to prevent turning therebetween. During the driving of the handle I! onto the blade, the ferrule l6 prevents the handle from splitting. As clearly shown in the completed screw driver (Fig. 1) the outer end surfaces of the ferrule l6 and the handle 12 abut annular surfaces formed on the shouldered sleeve l4.

From the above description it will be apparent that by practicing the method of this invention a composite screw driver blade may be economically and efliclently produced, the parts being integrally united in such a manner that a sturdy and durable composite blade is effected.

indrical shank of low carbon steel embeddedin the handle and secured thereto with longitudinal fins on the periphery of the shank, a blade portion of high carbon steel having a smaller cross section than the cylindrical shank welded to the end of the shank in axial alignment therewith, a stepped collar of low carbon steel encircling the blade and welded to the end of the cylindrical shank and to the blade, said collar having a cylindrical portion of the same diameter as the shankto support the handle and having an enlarged ring at one end, and a conical metal ferrule engaging the end portion of the handle surrounding the welded joint and supported by the enlarged ring on the collar;

CARL M. UNDERWOOD. ARDEN L. VAN NEST. 

